

Class T^4g 

Book_ _ 

GcpigM?._ 


COPYRIGHT DEPOSITS 































TWENTY LESSONS IN 

Locomotive Fuel Economy) 

:: :: EXAMINATION :: :: 
QUESTIONS AND ANSWERS 

THREE EXAMINATIONS 

. . . BY FREDERICK J. PRIOR . . . 

o 

BEING ONE OF THE SERIES OF THE PRIOR SYSTEM 
OF SELF-EDUCATIONAL TEXT AND REFERENCE BOOKS 


Published by 

FEDERAL RAILWAY INSTITUTE 

FOR 

SELF INSTRUCTION 







COPYRIGHT 1918 

BY 

FREDERICK J. PRIOR 
All Rights Reserved 


©Gl. A 4 9 8 6 4 4 


JUM 19 1318 




15 




I 


TO 


!Mm ^ (Emtsljaftt'r 

once a raitroab man, nofrr a successful ntait 
of affairs, ftiljo tjas attained marked 
hisiinciion, itjis kook is affcc- 
tiouatelg bekicaleb Jbjj its 
auiljor. 

H 






TABLE OF CONTENTS 


Page 

Foreword . 7 

Introduction . 9 

Customary Rules . 10 

Importance of Fuel Economy. 11 

Qualifications of Enginemen. 13 

Formation of Coal. 15 

Composition of Coal. 17 

Table of Coal Constituents. 18 

Heat . 19 

Combustion of Coal. 20 

Combustion of Coal—Continued. 22 

Combustion of Coal—Continued. 24 

Table Showing Colors of Degrees of Heat. 24 

Combustion of Coal. 27 

Longitudinal Sectional View of Boiler. 29 

Steam Chest and Cylinder—Illustration. 31 

Sectional View Through Steam Chest and Cylinder 32 

Sectional View of Smoke-Box and Stack. 34 

Firing With Bituminous Coal. 37 

Firing With Bituminous Coal—Continued. 41 

Firing With Bituminous Coal—Continued. 44 

Different Ways of Firing—Illustrations. 45 

Different Ways of Firing—Illustrations. 46 

Different Ways of Firing—Illustrations. 47 

Bituminous Coal Firing—Continued. 50 

Bituminous Coal Firing—Continued. 52 

Economical Boiler Feeding. 54 

Table Showing Variation of Temperature of Boil¬ 
ing Water and Steam. 55 

Boiler Feeding—Continued . 57 

Boiler Feeding—Continued . 60 

Economical Use of Steam. 63 

Sectional View Through Steam-chest and Cylin¬ 
der, Showing Steam Expansion. 64 

Examples of Various Cut-offs. 67-68 

Use of Steam—Continued. 71 

Locomotive Indicator—What It Shows, and How 75 

Indicator Diagram . 78 

Proof of Economy of Short Cut-offs. 78 

Indicator Diagram . 79 

Full Throttle . 79 

Steam Throttled . 80 

Combination Diagram . 81 











































































FOREWORD. 

“Instruction is only half the battle,” says Emer¬ 
son. 

It is safe to say there is no other class of labor that 
more fully realizes the truth of this than locomotive 
enginemen. 

Locomotive Firemen must have technical instruc¬ 
tion, must study, must have practical experience, and 
must pass graded examinations before qualifying 
as locomotive engineers. 

Locomotive Engineers must continually search 
after knowledge. The instruction previously received 
being intended to bring out their latent strength. 
The experience, labor, observation and practice they 
get in the school of hard work all combine to de¬ 
velop and perfect what is so absolutely essential— 
GOOD JUDGMENT. 

To earnest men seeking to develop the “MASTER 
MIND” and to be masters of their work, study of 
seemingly dry subjects becomes interesting; espe¬ 
cially when, as in this book, a sincere effort has been 
made to invest even dry topics with an interest that 
fascinates and instructs. 













































































INTRODUCTION. 


These questions cover the Three Examinations 
embodied in the Twenty Lessons on Locomotive 
Fuel Economy as required by some railroads. 

It would be foolish to think for a moment that 
these answers may be copied or learned for the pur¬ 
pose of passing the required examinations. 

The book of “Instructions for Locomotive Fuel 
Economy” furnished to engineers and firemen by 
the railway company must be thoroughly studied in 
order to have a proper understanding of these 
definite answers, every one of which is based upon 
the instructions contained in the book mentioned. 

Moreover, when reading the questions and their 
answers the Instruction Book should be at hand to 
be studied in connection with them. Notice that at 
the beginning of each question there are enclosed 
in brackets, the letter T and a number. The letter 
T refers to the topic (or subject) of the question 
and its answer, and the number refers to the num¬ 
ber given to the topic at the beginning of each topic 
in the Instruction Book. These topics should be 
read over many times if necessary, in connection 
with each question and its answer. Only by doing 
this and combining EXPERIENCE and OBSER¬ 
VATION with this study can a clear and thorough 
understanding be had of the purpose and meaning 
of each question and its answer. 


CUSTOMARY RULES 


Governing Manner of Writing Examinations as Re¬ 
quired by Some Railway Companies. 

The three Examinations may be written at one 
time, or at different times, as the Student prefers. 
More than one sitting for each Examination will be 
allowed if necessary; but the Student should prepare, 
by careful study, to go through at least one complete 
Examination at each sitting. 

The Examinations are to be written by the Student 
before an Officer of the Company or his Representa¬ 
tive. Consulting the Instructions, while doing this, 
will only be permitted to answer the ^ questions. 

Give clear, correct and short Answers. The num¬ 
ber in parentheses with each question indicates the 
Topic that treats the Subject. 


FIRST EXAMINATION 

ECONOMICAL FIRING 


LESSON I.—IMPORTANCE OF FUEL 
ECONOMY. 

1. (T-l) What is the first necessity of every 
working locomotive? 

Sufficient steam for the work it must do. It is 
a vital necessity. The motive power is absolutely 
dependent upon steam. 

2. (T-2) What is the Company’s annual expense 
for locomotive fuel? 

(State the sum if known.) 

3. (T-2) Why is economy in the use of fuel 
necessary? 

Because fuel is property and should not be wasted 
or destroyed. Next to wages fuel is the largest 
outlay the Company has. It is as necessary to be 
careful of fuel and to practice economy in its use 
as it is to avoid smashing cars or doing damage to 
other property of the Company. 

4. (T-2) Do you appreciate the necessity of 
economizing in the use of this most expensive sup¬ 
ply as much as possible? 

Yes, because I understand that it is for use, not 
waste. That it costs money and should be used so 
as to produce all the heat it is capable of giving; 
which may be done by properly firing it. 

5. (T-2) Do you earnestly try to do so? 

I do. 

6. (T-3) Why is smoke produced about sta¬ 
tions objectionable? 



12 


Locomotive Fuel Economy 


Because it befouls the air, creates a nuisance and 
gets the Company into bad repute. And it gives 
evidence of poor firing, imperfect combustion and 
resultant waste. 

7. (T-4) Can the labor of firing be lightened by 
intelligent management of the fire? 

It can very much. By using brains in the exercise 
of good judgment, muscular exertion is lessened. 
Good work can be done by the Fireman in doing 
his part in generating steam. He should take pride 
in doing perfect work. 

8. (T-6) Who handles the fuel? 

The fireman does. 


Locomotive Fuel Economy 


13 


LESSON II.—QUALIFICATIONS OF ENGINE- 
MEN. 

9. (T-8) What is an engineer’s or fireman’s 
most necessary mental quality? 

Good judgment. It correctly measures all condi¬ 
tions; speedily when necessary, and guides the fire¬ 
man to do the right thing at the right time. It is 
not enough to KNOW because unless ALL the con¬ 
ditions that surround the work are taken advantage 
of and good judgment is used he will make blunders. 

10. (T-8) Do you strive to always exercise it in 
your work? 

The student ought to be able to answer most em 
phatically that he does. 

11. (T-9) Name the ways in which engineers 
and firemen should co-operate to avoid waste and 
loss of fuel and unnecessary labor in firing. 

Engineers should tell firemen about unusual stops 
to be made so that the fire can be regulated to save 
coal and both should co-operate and work together. 
Firemen should keep in mind what engineers tell 
them and act upon it, using their best judgment. 

12. (T-9) Should you be careful about over¬ 
loading your tender with coal at chutes and pre¬ 
venting the loss of coal overboard while running? 

I should be and the engineer should co-operate. 
Unless there is harmony between us and we work 
well together it makes harder work for me. The 
engineer should tell me of all unusual stops so I 
can regulate the fire accordingly; and both of us 
should take care to prevent waste of coal at chutes, 
or while running. 

13. (T-9) Why should you not permit long 
standing accumulations of coal on any part of your 
tender? 

Because it loses heating value when exposed to 


14 


Locomotive Fuel Economy 


air and weather. It should be often shoveled ahead 
and when used, replaced by fresh coal. 

14. (T-10) What should be a fireman’s attitude 

toward his engineer, and his engineer’s instructions 
while on the road? 

He should be willing to learn and profit by the 
experience and advice of his engineer. He should 
put into actual practice the best methods of work, 
as shown him by the engineer. He should always 
remember that the engineer is in full charge of the 
locomotive and that he is responsible for its condi¬ 
tion, safety and performance. Therefore, while on 
a trip the fireman should respect his authority and 
carry out his instructions. 


Locomotive Fuel Economy 


15 


LESSON III.—THE FORMATION OF COAL. 

15. Have you carefully read the description in 
this Lesson of the formation of coal? 

Yes. And it is very interesting to learn exactly 
how a fire burns and to know why it burns. 

16. (T-ll) Was the earth always as cool as it is 
now? 

No. It was once as hot as the sun now is. It was 
a fiercely burning mass of flaming gases—just exactly 
as the sun now is. In the course of ages and ages 
these flaming gases became liquids. White hot or 
red hot incandescent liquids which, after millions of 
years, gradually cooled. The terrific conflagration 
that raged for ages produced what nearly every 
ordinary fire produces—carbonic acid gas and steam 
—but in vast quantities. Almost every fire produces 
carbonic acid gas and water, but the heat converts 
the water into steam. So with the terrific fire of the 
earth ages and ages ago. The tremendous volumes 
of steam rising to the cold altitudes condensed to 
water and fell upon the earth’s then incandescent 
crust in great downpours of rain. The rain im¬ 
mediately became steam again, rose to cold alti¬ 
tudes and again fell as rain. This was repeated over 
and over for ages, and helped to cool the gradually 
thickening crust, absorbed its heat and carried it 
away, until finally the crust was cool enough for 
vegetable and animal life. 

17. (T-12) Does vegetation grow now as large 
and abundantly as it did when the world was 
younger? 

It does not. Great trees grew four or five feet 
thick, almost branchless and of great height. They 
grew very fast, had a pithy interior, had very little 
strength as wood, but were good for coal formation. 
Heavy carbonic acid gas enveloped the globe, mak¬ 
ing human life impossible at that time. The crust 
was fissured and cracked with gaping openings from 


16 


Locomotive Fuel Economy 


which poured great volumes of vaporous gases from 
the fiery interior. In this atmosphere vegetation 
grew in rank profusion. Some with stems two to 
three feet in diameter, like giant corn-stalks, grew 
forty to fifty feet above a great mass of huge ferns. 
There must have been perpetual summer, a continual 
blaze of tropical heat and sunshine, dense humidity 
and warm vapors, resulting in enormous growths of 
sappy vines, huge ferns, and resinous sticky weeds 
of tremendous size. 

18. (T-13) What happened to vast quantities of 
trees and vegetation that first grew on the earth? 

Whole forests were buried. For ages the earth’s 
crust was comparatively thin so that the awful in¬ 
ternal disturbance caused fearful earthquakes which 
rent the crust asunder burying great forests under 
sand and clay. These made new soil from which 
sprang fresh growths of trees and vegetation. 

19. Name two ways in which this early vegetable 
matter was buried. 

By internal disturbances causing fearful earth¬ 
quakes. By the action of rivers carrying great 
quantities of drift wood and logs which were buried 
in the mud along the banks. 

20. Describe in a general way how coal was 
formed. 

The buried wood and rank vegetation became a 
soft black substance that retained all the elements 
of wood, but in a changed form. This was grad¬ 
ually compressed by the enormous pressure above it, 
caused by great rocks and vast quantities of soil, 
hundreds, sometimes thousands, of feet in depth. 

The vegetation and great trees first became a soft, 
black substance then gradually became hard as it 
was pressed upon by the frightful pressure above, 
until, finally, it became coal. 


Locomotive Fuel Economy 


17 


LESSON IV.—THE COMPOSITION OF COAL. 

21. (T-16) What substance forms the chief part 
of both anthracite and bituminous coal? 

Carbon. It forms the chief part of all kinds of 
coal. It is the part that burns in the solid, or coke 
state, on the grates. It is the coke of coal and the 
charcoal of wood. Both forms are reached by prac¬ 
tically the same process. 

22. (T-16) What was this substance formerly? 

It was carbonic acid gas of the atmosphere which 
passed into the form of wood as the vegetation grew 
and so became carbon. 

23. (T-17 and 18) Which has the most “fixed” 
or solid carbon, bituminous or anthracite coal? 

Anthracite coal. (It has about 85 per cent.) It 
also contains 5 per cent gaseous matter and moisture 
and 10 per cent ash. Thus Anthracite is almost all 
“fixed” carbon. That is why it burns on the grate 
in a solid state, with very little flame. 

24. (T-18) Which has the most gaseous matter? 

Bituminous. (It has 40 to 50 per cent.) It also 
contains 40 to 50 per cent of “fixed” carbon and 
about 10 per cent of incombusible matter (or ash). 
It is because Bituminous has about one-half gaseous 
matter that it burns above the solid fire of carbon 
as flame, or else produces smoke. 

25. (T-18) What well known form of manu¬ 
factured fuel does anthracite coal resemble? 

Coke, which is made by heating coal in a retort 
from which air is excluded and permitting the gas 
to escape from it, leaving only solid carbon. 


18 


Locomotive Fuel Economy 


The following table shows the principal con¬ 
stituents of the coal used by the leading rail¬ 
ways, the only percentages not shown in the 
table being made up of ash, moisture and sul¬ 
phur: 


Average 

Fixed 

Carbon 

Volatile 

Matter 

Av. Heat 

Units 

Per Pound 

Anthracite. 

Average of four districts. 

83.77 

3.86 

13,169 

Semi-Bituminous. 

Average of six districts in 
Pennsylvania and W. Virginia 

73.75 

18.15 

14,673 

Pocahontas . 

74.39 

21.00 

15,070 

Bituminous. 

Average of eighteen districts 
in Pennsylvania, Ohio, West 
Virginia, Kentucky, Ten¬ 
nessee, Illinois . 

Highest of above. 

52.25 

34.75 

13,000 

60.99 

32.53 

15,200 

Lowest of above. 

37.10 

35.65 

13,800 

Illinois Bituminous. 

Thirty-seven districts . 

48.02 

35.58 

12,210 

Iowa Bituminous. 

Five districts . 

37.47 

38.44 

13.400 

Missouri Bituminous. 

Five districts . 

48.73 

37.67 

14,150 

















Locomotive Fuel Economy 


19 


LESSON V.—HEAT. 

26. (T-19) What is the Source of Power of all 
steam engines? 

Heat. It is the only means by which water can be 
converted into steam, giving it all the power of 
EXPANSION it may have. It is only by its power 
to expand that steam is able to do the powerful 
work it does in the cylinders of an engine. It ex¬ 
pands from a small volume at high pressure to a 
large volume at low pressure. Heat first produces 
steam from water, then as more steam is added high 
pressure is obtained, so HEAT is the source of 
steam power. 

27. (T-20) What is a Unit of Heat? 

The amount of heat required to raise the tem¬ 
perature of a pound of water (at 32 degrees F.) one 
degree. A pound of water is one pint. One unit 
of heat is just enough to warm a pint of water (at 
32 degrees F.) one degree; two units of heat will 
warm it two degrees, or it will warm two pints one 
degree. Thus a hundred units will heat a hundred 
pounds (or pints) of water one degree, or it will 
heat one pint of water a hundred degrees. 

An actual test, although somewhat crude, may be 
made by holding a lighted match under a thin metal 
vessel containing a pint (one pound) of water. It 
will heat the water two degrees, and it will produce 
two units of heat; therefore, one unit of heat is 
obtained by burning about half-a-match, or the 
amount of heat usually necessary to light a cigar. 


20 


Locomotive Fuel Economy 


LESSON VI.—THE COMBUSTION OF COAL. 

28. (T-21) Man exerts his power over the world 
chiefly through what means? 

Fire. It enables man to multiply his powers of 
production and transportation through the endless 
work of countless steam engines in shops and fac¬ 
tories, on ships, in mines and on locomotives. 
Through the operations of FIRE the power of man 
is successfully exerted and maintained. We may be 
said to live by the aid of fire. Its power is con¬ 
verted into useful work, and this is accomplished 
through the processes of COMBUSTION. 

29. (T-21) Is it, then, reasonable and necessary 
that firemen and engineers should thoroughly un¬ 
derstand the burning of a FIRE? 

It certainly is. Besides it is a very interesting and 
fascinating study, that may be easily understood. 

30. (T-22) What is the air composed of? 

Chiefly of two invisible gases: oxygen and nitro¬ 
gen. 

31. (T-22) The air is made up mostly of which 
gas—Oxygen or nitrogen? 

Nitrogen. 

32. (T-22) Which part of the air makes the fire 
bum? 

It is oxygen that makes the fire burn. It is often 
called “the supporter of combustion,” but as a matter 
of fact it is as much fuel of the fire as the coal. Ap¬ 
parently both are consumed in burning, but in reality 
neither is destroyed. Both combine—CHEMICAL¬ 
LY—to produce a new substance. The coal disap¬ 
pears as coal and the oxygen disappears as oxygen, 
but if the conditions permit a perfect union they 
reappear as CARBONIC ACID GAS. 

33. (T-23) Which part of the air is inactive in 
the burning of the fire? 


Locomotive Fuel Economy 


21 


Although nitrogen is the larger part of the air, 
it is inactive in combustion (or burning). It does, 
however, hold back the activity of the oxygen. 

34. (T-23) What would happen to a locomotive 

with a fire in its interior, if the whole of our atmos¬ 
phere were oxygen? 

It would burn up more rapidly than the coal. Be¬ 
cause without the restraining power of Nitrogen iron 
would burn. It can be tested by a simple experi¬ 
ment. A piece of iron set light to in a jar of oxygen 
goes on burning to the end. Thus a fire burning on 
an iron grate burns ON it because of the nitrogen 
being there. If the air were pure Oxygen the grate 
would burn more fiercely than the coals, for the 
reason that under that condition the iron would be 
even more combustible. 


22 


Locomotive Fuel Economy 


LESSON VII.—THE COMBUSTION OF COAL 
—Continued. 

35. (T-24) Name the two ways in which sub¬ 
stances unite. 

Mechanically and chemically. 

36. (T-24) Describe the difference between a 
mechanical and a chemical mixture. 

Substances united mechanically do not change. 
Substances united chemically combine and become 
a new and different substance. 

37. (T-24) Is the combustion of coal a chemical 
or a mechanical combination? 

It is a chemical combination. When the two gases 
known as Oxygen and Hydrogen unite chemically 
in the proportion of TWO atoms of hydrogen and 
ONE atom of oxygen the result is a fire—a very 
hot fire—which PRODUCES from the two invisible 
gases a new substance not like either of them; this 
new substance is—WATER. The difference between 
a chemical and a mechanical mixture is that sub¬ 
stances mechanically combined mix with each other, 
but do not change. Whereas, in a chemical mixture 
they combine to produce a NEW substance. Thus 
if a piece of charcoal is heated red hot its particles 
or atoms will COMBINE CHEMICALLY with the 
atoms of the oxygen gas in the air and a hot fire 
is the result. The fire produces a new substance 
from the chemical combination unlike either the char¬ 
coal or the oxygen gas—known as: CARBONIC 
ACID GAS. 

★ 38. (T-25) What difference is there in the 

amount of HEAT produced when carbon burns to 
CARBONIC ACID gas and CARBONIC OXIDE 
gas, respectively? 

When carbonic acid gas is produced a pound of 
carbon yields 14,500 heat units. When carbonic 
oxide gas is produced it yields only 4,452 heat units 
per pound of carbon. Bituminous coal has about 50 


Locomotive Fuel Economy 


23 


per cent of gaseous matter which is composed chiefly 
of hydrogen, oxygen and nitrogen, and carbon vapor. 
These gases are liberated by the fire. If there is 
enough air to provide the oxygen required and if 
the temperature (bright red) 1,800 degrees F. pre¬ 
vails in the fire box, they are burned. This degree 
of heat is called “the temperature of ignition.” The 
atoms from the coal and the atoms of oxygen have 
such tremendous attraction and they rush together 
with such fearful speed that they CLASH, and 
light and heat result from their clashing together. 

TWO atoms of oxygen and ONE atom of car¬ 
bon result in perfect combustion producing CAR¬ 
BONIC ACID GAS; but, when through insufficient 
air being supplied, ONE atom of oxygen and ONE 
atom of carbon unite, it results in imperfect com¬ 
bustion which produces CARBONIC OXIDE GAS. 

39. (T-25) In combustion, which bums first— 
the gaseous or solid part of the coal? 

The gaseous. The hydrogen gas separates from 
the carbon vapor and combines with the oxygen 
available (two atoms of hydrogen with one atom of 
oxygen)—and steam is the result. 

In its turn the carbon vapor gives up ONE of its 
atoms to TWO atoms of oxygen and, in that pro¬ 
portion combines (chemically) with oxygen and is 
burned. It is in this way that the GASEOUS part 
of the coal is burned first. 

40. (T-26) Does the burning of coal produce 
steam in the FIRE? 

Yes. It does produce steam in the fire. 

41. (T-26) If not, explain why. If so, explain 
how. 

Steam in the fire is caused by the combination of 
two atoms of hydrogen gas with one atom of 
oxygen gas, producing the greatest heat known; and, 
strange as it may seem, also steam which condenses 
to water. 


24 


Locomotive Fuel Economy 


LESSON VIII.—THE COMBUSTION OF COAL 
—Continued. 

42. (T-27) How hot must anthracite coal get 
before it will ignite and burn? 

It must get red hot. It requires a higher tem¬ 
perature for ignition than Bituminous coal so it 
must be heated red hot because it contains but little 
gaseous matter. It burns with a short, transparent 
flame and makes but little smoke. Burns much like 
Bituminous coal burns after the gaseous matter has 
been liberated, because it is nearly all solid or “fixed” 
carbon. 

43. (T-27) Which coal catches fire easiest, an¬ 
thracite or bituminous? 

Bituminous. Because of the easily ignited im- 
fiammable gases it contains. 


The temperature of the firebox is one of the 
basic requisites of good firing. When the loco¬ 
motive is properly fired and the consumption is 
at the ratio of about 20 pounds of air to each 
pound of coal the firebox temperature will be 
about 2,000 degrees F., the ideal temperature for 
perfect combustion. The ignition temperature of 
coal is between 1,800 degrees and 1,900 degrees 
F., and the maximum firebox temperature should 
be between 2,000 and 2,500 degrees F. The fol¬ 
lowing shows the colors for the various degrees 
of heat: 


1,300 degrees F. 

1.600 degrees F. 
1,850 degrees F. 
2,200 degrees F. 
2,400 degrees F. 

2.600 degrees F. 


Fire in dull red. 

Fire in full cherry red. 
Fire in bright red. 

Fire in bright orange. 
Fire in. white heat. 

Fire in' welding heat. 


44. (T-28) How does the burning of coal cause 

heat? 

By the rushing together at tremendous speed of 
the atoms of oxygen and hydrogen, called “chem¬ 
ical affinity.” The solid part of coal—both authracite 



Locomotive Fuel Economy 


25 


and bituminous—is impure carbon. A diamond is 
pure carbon. If a diamond made fast to a loop of 
platinum wire is heated red hot in a flame and is 
then plunged into a jar containing oxygen gas it 
instantly glows like a little star, with a pure white 
light. It is caused by the atoms of oxygen striking 
against this diamond on all its sides. They are 
irresistibly attracted by CHEMICAL AFFINITY; 
an attraction of the same mechanical quality as grav¬ 
ity. Every oxygen atom as it strikes the surface has 
its motion destroyed by its impact with the carbon, 
and the motion produces the most intense HEAT. 
The attractions are so mighty that the brilliant gem 
is kept white-hot, and its atoms unite with the oxy¬ 
gen and fly away as carbonic acid gas. This experi¬ 
ment has been made and described by Professor 
Tyndall. 

45. (T-29) Why does the breaking of coal into 

small lumps aid its burning? 

Because of the greater surface it gives for the 
contact of the oxygen gas of the atmosphere. Only 
a two-million-three-hundred-thousandth part of the 
heat from the sun reaches the earth. Surely, a very 
small part! The total heat of the sun radiating from 
it in all directions is beyond our comprehension. 
How is its heat produced? Professor Tyndall says 
it is produced by meteors that shower down upon 
the sun exactly as the atoms of oxygen showered 
against the diamond burning experiment. Whether or 
not this theory is correct, there is a widely accepted 
theory that the heat of the sun is caused by BLOWS 
against it. In other words, meteors rushing toward 
it, drawn by its powerful attraction—just as bodies 
are drawn to earth by the attraction of gravitation— 
strike the sun with terrific force and generate its 
heat. 

We know BLOWS produce heat. A nail on an 
anvil can be struck with a hammer until it becomes 
too hot to hold. Loose rods sometimes pound 
crank-pins and make them so hot that the babbitt 
metal is melted. 


26 


Locomotive Fuel Economy 


Coal in a furnace—after the gaseous matter has 
been expelled from it—is burned under similar con¬ 
ditions as the diamond in the jar was burned. The 
speed of combustion determines the degree of heat 
—its intensity or otherwise, and this, in turn, de¬ 
pends to a great extent upon the SURFACE of the 
coal against which the atoms of oxygen can strike. 
That is WHY coal should be broken to small sizes 
and spread over the fire to EXPOSE the largest 
possible SURFACE for contact with the oxygen of 
the air. 


Locomotive Fuel Economy 


27 


LESSON IX.—THE COMBUSTION OF COAL 
—Concluded. 

★ 46. (T-30) What amount of air is required in 

practice for the burning of each pound of coal? 

About 12 lbs. of air, or 150 cubic feet (at 32 de¬ 
grees F.) is needed for perfect combustion, although 
in actual practice it is necessary to supply twice 
that amount in order to insure enough oxygen. One- 
fifth of the air is oxygen. This proportion is the 
same throughout the surface of the earth, whether 
high above it or deep below it. Therefore, a fur¬ 
nace can be provided anywhere with the needed 
amount of oxygen for the combustion of its fuel by 
arranging some means of drawing into it a known 
quantity of air; usually a chimney or stack. 

47. (T-30) What is Natural Draft? 

A chimney for drawing a known quantity of air 
to the furnace up from beneath and through the fire 
by the motion of an ascending column of hot air 
and gases. 

48. (T-30) What is the cause of Natural Draft 
through a chimney? 

Gravity, the force that pulls everything, including 
the air to the earth. Weight of any object is a 
manifestation of gravity. Air at sea level weighs 
about 15 lbs. per square inch. It is the result of this 
pulling force of gravity. When two liquids or gases 
are mixed together GRAVITY forces the lightest 
one to RISE through the mass of the heaviest one, 
so that gravity may pull down the heavier of the two. 
That is WHY oil rises rapidly through water and 
floats on its surface. Bubbles of steam, or gas, or air 
do the same. Air when it is warmed EXPANDS 
and takes more space than when it was cooler, be¬ 
cause it is LIGHTER than before it expanded. 
When surrounded by cool air it RISES through the 
cool and heavier air. That is WHY mixed hot-air 
and gases in a chimney or stack RISE, leaving a 


28 


Locomotive Fuel Economy 


partial VACUUM behind, causing the air below to 
rush in. That is HOW the NATURAL DRAFT 
through a fire and a chimney is caused. 

49. (T-31) Is the natural draft sufficient to pro¬ 
duce enough steam for a working locomotive? 

No, it is not, when running. The natural draft 
acts upon the fire in a locomotive while the engine 
is not working, but while the engine is running great 
and intense heat is needed to make the steam used. 
To make this steam the water must boil very rapidly, 
because about half a barrel of water is converted into 
steam every moment while the locomotive is run¬ 
ning, and sometimes when the load is very heavy, 
the traction poor, or the speed extra fast, a barrel 
of water every minute is often used to make steam. 

50. (T-31) Is a stimulated draft necessary? 

Yes, because of the continuous heat needed to 
boil the water rapidly. This heat is obtained by a 
fire surface of from twenty to forty square feet. 

51. (T-32) If a stimulated draft is necessary, 
how is it obtained? 

By the steam which escapes up the chimney (or 
stack) after it has done its work in the cylinders, 
commonly called the “exhaust.” It creates a draft 
so strong and powerful that sometimes lumps of coal 
as large as walnuts dance up and down like drops 
of water on a red hot stove until finally they are 
burned, or else are reduced to the size of peas and 
then are driven through the tubes and shot from the 
stack like rockets. 

52. (T-32) What is your understanding of an 
“exhaust” of a locomotive? 

It is the steam that leaves the cylinder on both 
sides and rushing through the exhaust pipe shoots 
up the stack, making the noise called puffing. 

53. (T-32) Is it your understanding that the 


u 

. V 

* e- 

u d • 
rt O ^ 

£ <u J-H 

v> D 

• ^ »■ "H ; f-^ 

■M 

^ E.b ^ 
£c/)0<; 

C^OlCiH 


. <U 

_ &« 
3 2 *p> 

u 

c/^jM 2 2 

rj u V 2 tJ 

g 1)^ 5 
& +•> o~cc 

rl ^ OJ 



PQU 



































































































































































30 


Locomotive Fuel Economy 


“exhausts” of a locomotive are a successive number 
of the same thing? 

It is. It might be called a continuous endless 
number of liberated prisoners rushing to freedom 
after having been imprisoned and compelled to labor. 
The “exhausts” shoot up the stack with great force 
and rapidity in their rush to the atmosphere and 
freedom, but as fast as each “prisoner” is set free 
another one takes its place as it leaves the boiler 
to do its work and follow the others. 

54. (T-32) Tell briefly and in your own way 
how the “exhausts” are made to produce the neces¬ 
sary draft through the fire, on a working locomotive. 

The steam is contracted in its passage through the 
nozzle and so is given extra force and speed as it 
shoots up the exact center of the smoke stack. 
Ascending in a constantly expanding volume it 
creates a partial vacuum (or empty space) in the 
smoke box; this draws air through the grates and 
fire and tubes to the smoke box, the steam exhaust 
catches it and hurls it upward and a strong forced 
draft is caused. The illustration of a “Longitudinal 
Sectional View of a Locomotive Boiler,” Fig. 1, ex¬ 
plains this. 

For example: When the throttle-lever is pulled it 
opens the throttle-valve in the stand-pipe. This pipe 
extends up into the dome. Steam is taken from the 
upper part of the dome so as to get as dry steam as 
possible—that is to say, steam without spray from 
the boiling water. From thence it is sent direct to 
the cylinders to expand and exert its force. Steam 
flows from the steam space (K) into the stand-pipe, 
then down the dry-pipe through which it reaches the 
front-end or smoke-box. Then it enters the steam- 
pipes, rushes down them to the steam passages in 
the cylinder-castings, to the steam-chests on top of 
the cylinders. Steam accumulates in the chests from 
which it rushes into the cylinders on either side of 
the locomotive by the movement of the valves. The 
illustration: “Sectional View Through Steam Chest 



ot* 


os 

w 

G 

£ 

HH 

G 

>< 

U 

Q 

55 

< 

H 

c/2 

W 

X 

u 

< 

w 

H 

C/5 


O 

D 

O 

OS 

X 

H 

£ 

w 


G 

< 

55 

O 

HH 

H 

U 

W 

C/5 


o <u 


.2 o 


CNJ 

'EL 

d 

HH 

G 


<D 4-| 
































































































































32 


Locomotive Fuel Economy 


and Cylinder” (Fig. 2) shows the inside arrange¬ 
ment of a steam-chest and cylinder. Imagine it to be 
cut length-wise, through the center. AA is the space 
inside the steam-chest, full of live steam just from 
the boiler, ready for admittance to the cylinder. 
D is the piston just completing a forward stroke. 
The valve gear mechanism is so arranged that slide- 
valve B is now being pulled backward, its front edge 
uncovering the front-steam-port opening, steam is 
entering steam-port CC, is flowing to the cylinder 
wherein it will push the piston backward. That is 
HOW steam reaches the cylinder and does its work. 
Next is shown HOW steam leaves the cylinder and 
WHAT it does after leaving. (See Figs. 3 and 4.) 

The arrows in the illustration are intended to show 
the movement of the steam that pushed the piston 
forward when completing the stroke as shown. 
Through the position of the valve B this steam, 



FIG. 3. SECTIONAL VIEW THROUGH STEAM CHEST 
AND CYLINDER. 

Showing action of exhaust steam in leaving the cylinder. 


now being exhausted, escapes the way it entered the 
cylinder EE to the exhaust-cavity in the valve F, 
then into the exhaust-passage G, through which it 
rushes to the exhaust-pipe shown in AA. The illus¬ 
tration “Sectional View of Locomotive Smoke-Box 












Locomotive Fuel Economy 


33 


and Stack” (Fig. 4) shows this steam rushing up 
the smoke-stack to the atmosphere. These escaping 
“cylinder-fulls” of steam rushing upward with great 
speed, one after the other, cause the report called 
“puffing,” of which there are sometimes many in a 
second. Each “puff” represents a “cylinder-full” of 
escaped steam that has gone through several move¬ 
ments in doing its work, and even as it rushes away 
it is made to serve a purpose in creating A FORCED 
DRAFT. 

The illustration (Fig. 4) shows a LOCOMOTIVE 
FRONT-END ARRANGEMENT, consisting of the 
smoke-stack, smoke-box and exhaust-pipe and noz¬ 
zle; cut in half, straight up and down. BB shows 
the ends of the exhaust-passage leading from the 
right and left cylinders. AA is the exhaust-pipe into 
which the steam “exhausts” from the cylinders on 
either side are admitted, to be directed upward to 
the EXACT CENTER of the smoke-stack. Finally 
they are contracted in their wild rush to escape, be¬ 
cause they are forced to pass through the nozzle N. 
This contraction gives them extra force and greater 
velocity (or speed) to perform their last work as 
they shoot up the stack. 

The artificial or “forced draft” thus created is 
regulated in its effect upon the fire by the work 
the engine does. Light work requires less steam 
than heavy work. When but little steam is used the 
exhausts escape softly and create a light draft. 
Heavier work uses more steam, and the larger 
amount exhausted creates stronger drafts. 

55. (T-33) What is meant by “rate of com¬ 
bustion?” 

The weight of fuel burned on each square foot of 
grate surface in an hour. 

56. (T-33) Is the very rapid burning of coal 
economical or wasteful? 

It is very wasteful. Coal is burned rapidly when 
there is not enough TIME allowed for the union 


34 


Locomotive Fuel Economy 



FIG. 4. SECTIONAL VIEW OF LOCOMOTIVE SMOKE-BOX 
AND STACK. 

Showing the action of exhaust steam in escaping up the smoke¬ 
stack. Determined by tests conducted by a committee of 
the American Railway Master Mechanics’ Association. 














Locomotive Fuel Economy 


35 


of the atoms to produce perfect combustion. The 
gaseous portion of coal, especially needs TIME. If 
not given time it escapes as dense smoke and is 
needlessly wasted. There must be enough time to 
supply sufficient air as well to the coal burning on 
the grates. The RATE OF COMBUSTION should 
be as LOW as possible. 

57. (T-33) Which should a fireman do—aim to 
keep his “rate of combustion” as high or as low as 
possible, while supplying sufficient heat for keeping 
up steam? 

He should keep it as low as possible, without re¬ 
ducing the regular boiler pressure. 

58. (T-34) What is the “blower” used for? 

To create draft for the fire while the engine is 
standing. 

59. (T-34) Explain briefly how it causes a draft 
through the fire. 

It is caused by a small admission of steam through 
the blower pipe to nearly the tip of the exhaust 
nozzle. It causes a draft the same as the exhausts 
do, but much milder and steady. 

60. (T-35) Describe the proper use of the 

blower in raising the steam pressure. 

It should be used as lightly as the time needed to 
raise steam will permit. 

61. (T-35) Describe the proper use of the 

blower in working at the fire. 

It should be operated so as not to cause too rapid 
a rate of combustion. 

62. (T-35) If the steam pressure is increased, is 
there any change in the temperature of the boiler? 

Yes, the temperature is increased. It is im¬ 

portant to increase the temperature gradually, be¬ 
cause of the increase of boiler temperature as the 
steam PRESSURE is increased. For example: when 


36 


Locomotive Fuel Economy 


the steam pressure is increased from SO to 100 
pounds the temperature of the boiler is increased 40 
degrees, or almost one degree for each pound of 
pressure increase. 

It is because the BOILER EXPANDS when 
heated, that the rapid increase of steam pressure 
causes damage to boiler plates and stay-bolts, be¬ 
cause the rise in boiler temperature causes a too 
sudden expansion. On the other hand there is a 
corresponding fall in temperature with a decrease of 
steam pressure. That causes the boiler to COOL 
and CONTRACT. “Expansion” and “contraction” 
is the same as stretching and shrinking. These move¬ 
ments do damage to locomotive boilers. Hence it 
is important to always keep the steam pressure as 
steady as possible. 

63. (T-35) What change, if any? 

If the steam pressure is increased from 50 to 100 
pounds it increases the temperature of the boiler 40 
degrees. Sudden increase of boiler temperature 
causes expansion and grave danger to stay-bolts and 
plates. 

64. (T-35) If the steam pressure falls, is there 
any change in the temperature of the boiler? 

Yes; sudden cooling causes a lower temperature. 

65. (T-35) What change, if any? 

It causes contraction of the boiler and its parts. 

66. (T-35) In what way does changing steam 
pressure injure a boiler? 

Cracking of plates, breaking of stay-bolts, leaking 
flues and damage to flue sheets. 


Locomotive Fuel Economy 


37 


LESSON X.—FIRING WITH BITUMINOUS 
COAL. 

67. (T-36) On what does the fire in any fur¬ 
nace rest? 

The grates which serve as its foundation. 

68. (T-36) Are the grates of much importance 
in a fire-box? 

Yes, they are of vital importance, because fire is 
the life-giving power to an engine and upon the 
grates rests the source of the locomotive’s power; 
and they should receive proper inspection and han¬ 
dling. 

69. (T-36) Name the two most important duties 
of a fireman concerning his grates which must be 
attended to before starting. 

He must see that the ash pan is clear of ashes and 
that the grates are all level and connected. 

70. (T-36) Should grates be kept level, or other¬ 
wise? 

They should be kept level. 

71. (T-36) What may happen to the grates if 
they are not kept level? 

Some of the fingers of the grates might project 
into the fire and be burned off. Lumps of clinker 
might get wedged between fingers, allowing red-hot 
coals to fall into the ashpan to burn out the grates 
bodily. 

72. (T-36) When should a fireman be careful to 
place or lock his grates in a level position? 

Every time he moves the grates. 

73. (T-36) Describe a fireman’s proper inspec¬ 
tion of his grates and ashpan before starting on any 
trip. 

He should get down from the engine and look 


38 


Locomotive Fuel Economy 


carefully into the ashpan. He should notice whether ■ 
each bolt that connects the grates is in place. Should 1 
any defects be found they should be reported before 
starting out. 

74. (T-36) How should this inspection be made? 

Before starting on any trip. 

75. (T-37) Why should the grates be shaken 
while running? 

To prevent a thick bed of ashes or clinkers from 
forming to exclude the air from the fire. 

76. (T-37) The grates should be shaken about 
every—how many miles on freight engines? 

About every twenty miles. 

77. (T-37) On passenger engines? 

About every thirty miles. 

78. (T-37) When is the best time to shake the 
grates? 

When steam is shut off, or when draft through 
fire is light. 

79. (T-37) What would be the results if the 
grates were shaken too much? 

Smoke and cinders or unconsumed coal would be 
shot out the stack. This is wasteful. The best re¬ 
sults are to be had by shaking the grates just enough 
to shake the ashes into the ash-pan. It is only 
necessary to give free passage through them for 
air to reach the fire. 

80. (T-38) How are clinkers formed in the fire? 

By the accumulation of ashes that melt together. 

81. (T-38) How do they affect the fire? 

They prevent perfect combustion. 

82. (T-38) How can the formation of clinkers 
be partly prevented? 

By frequent shaking of the grates. 


Locomotive Fuel Economy 


39 


83. (T-38) What must be done with clinkers 
when they prevent the easy steaming of an engine? 

They must be removed by hooking out or knock¬ 
ing out as soon as possible. A good time to do it is 
when the train has a ten or fifteen minute wait, or 
while train is not using steam on a long down grade 
run. 

84. (T-38) Should clinkers be hooked or 
knocked out while the engine is using steam? 

• No. 

85. (T-38) Why? 

Because cold air would rush in while doing so 
and causing sudden contraction might do damage to 
boiler plates, tubes and tube sheets. 

86. (T-38) In discharging clinkers from an en¬ 
gine, in regard to what matters of safety must spe¬ 
cial care be exercised? 

To see there is no chance for them to strike any 
person or to fall on or near any bridge or culvert. 

87. (T-38) Ash pans and fires MUST NOT BE 
CLEANED near what places? 

Bridges, culverts, depots or buildings. 

88. (T-38) What part of the grates should 
clinkers be banked on, if there is no time or oppor¬ 
tunity to hook or knock them out? 

At the back of the firebox. 

89. (T-38) Why this part? 

Because there they do least harm in keeping air 
from the fire and when the chance comes can be 
quickly got rid of. 

90. (T-38) Should clinkers be worked at from 
the top or from the bottom of the fire? 

Always from the top of the fire. 

91. (T-39) When coal is burning—What is nec¬ 
essary to make it give off the most heat? 

Sufficient air. 


40 


Locomotive Fuel Economy 


★ 92. (T-39) In burning PERFECTLY, a pound 

of coal will make enough heat to evaporate how 
many pounds of water? 

About twelve pounds of cold water. 

★ 93. (T-39) In burning IMPERFECTLY a 

pound of coal will make enough heat to evaporate 
how many pounds of water? 

Four pounds of water. Imperfect combustion 
makes two-thirds less heat than perfect combustion 
does from the same number of pounds of coal. Thus 
less water is turned into steam. 

94. (T-39) Which is the most necessary “fuel” 

for the fire—coal or air? 

One is as necessary as the other, because both 
burn and help to make heat. 

★ 95. (T-39) About how many box-cars full of air 

must pass through the fire usually, to PROPERLY 
bum each charge of about four shovelfuls of coal? 

About eight box-cars full. 

96. (T-39) What condition should the bed of 
fire be in for the proper admission of sufficient air? 

Uniform in depth and in condition so air can get 
through it easily to the fresh coal on top of the bed. 

97. (T-40) Can too much air be admitted to the 
fire? 

Yes, because all air admitted over and above the 
quantity needed for perfect combustion absorbs the 
heat of the fire and carries it away. 

98. (T-40) What is necessary to guard against 
access of too much air? 

The full grate surface must be kept covered with 
fire. There must be no air holes, dead spots or bare 
spaces. 


Locomotive Fuel Economy 


41 


LESSON XI.—FIRING WITH BITUMINOUS 
COAL—Continued. 

99. (T-41) How long before leaving time should 
a fireman go on duty? 

At least 30 minutes. 

100. (T-41) When should he examine the con¬ 
dition of his fire? 

When he mounts his engine before going out. 

101. (T-41) In case the grates are not entirely 
covered with live fire—what should be done? 

Fresh coal should be put in and the grates com¬ 
pletely covered with live fire. 

102. (T-41) What should be seen to about the 
grates and ash pan? 

That tube sheets are free from honeycomb or 
clinker, ashpan clear of ashes and grates all level 
and connected. 

103. (T-41) What should be seen to about the 
smoke-box? 

That it is clear of cinders. 

104. (T-41) What should be seen to about the 
tube sheet? 

That there are no clinkers there. 

105. (T-41) At leaving time the steam pressure 
in the boiler should be at what point? 

As nearly as high as allowed. 

106. (T-41) At leaving time, the water level in 
the boiler should be at what height? 

As full as permitted. Usually three full gauges. 

107. (T-41) What about the inspection of the 
engine before leaving? 

It should be thorough, and it is important, because 


42 


Locomotive Fuel Economy 


it often prevents engine failures and delays on the 
road. 

108. (T-42) Briefly describe the proper condi¬ 
tion of the fire, steam pressure and water-level when 
the engine is ready to start. 

The fire should be level over all the grates and 
have a good bright bed. The steam pressure should 
be nearly as high as is permissible. The water level 
should show the boiler to be as full as allowable, 
usually indicated by the water glass being three- 
fourths full. 

109. (T-43) Should the fire-box door stand 
OPEN, or CLOSED, while the engine is starting? 

Closed, or on the latch. 

110. (T-43) Why? 

To prevent the chilling effect on the boiler that 
would result if the door were wide open for an in¬ 
rush of cold air. The door should be closed or put 
on the latch before the first steam exhaust escapes. 
The small opening in the door allows air enough to 
be drawn into the firebox to offset the “tearing of 
the fire” the strong draft produces. This results in 
fuel economy and prevents boiler injury. 

The fire should be in and the fire door closed or 
put on the latch every time before starting. On 
passenger engines, with light trains it is not always 
necessary to put in more coal before leaving every 
station. But on freight engines the coal put in before 
starting should be enough to last until the engine 
is put to working at a short cut-off. 

111. (T-44) Should a fireman pay attention to 
the height of the water-level in the boiler and the 
engineer’s habits of operating the injector? 

Yes, he should pay particular attention. 

112. (T-44) Supposing that the engine has run 
a mile with the injector suspended—should a “fire” 
be put in before or after the injector is started? 

Before. 


Locomotive Fuel Economy 


43 


113. (T-45) How should a fireman think and act 
concerning coming conditions of work? 

He should “anticipate” or think ahead of his work. 

114. (T-45) What condition should the fire be in 
when the steam is shut off? 

Neither low or fierce. Medium hot. 


44 


Locomotive Fuel Economy 


LESSON XII.—FIRING WITH BITUMINOUS 
C O AL—Continued. 

115. (T-46) Except in emergencies requiring 
full boiler pressure—should the fire be forced to 
rapidly regain lost pressure? 

It should not. 

116. (T-47) In a fire needing more coal—which 
places should first be covered with fresh fuel— 
places at a white heat, or places that have burned 
down to red? 

The red places must be first covered and next the 
bright or white places. 

117. (T-47) Describe briefly and in your own 
way the proper condition of the fire while running to 
produce the greatest heat with the least fuel. 

There should be a good bed about three or four 
inches deep, heavy at the corners and along the 
sides. The top of the middle portion level and the 
whole fire bright and white all over. 

118. (T-47) Is this the condition you try to keep 
your fire in? 

The student should be able to answer that it cer¬ 
tainly is. 

119. (T-48) Does it make much difference if in 
the bed of fire there are several square feet on which 
not much coal is burning? 

It does. 

120. (T-48) Should every square foot of the 
fire’s surface be made to do its share of work? 

It should. 

121. (T-48) On what part of the fire does the 
draft usually act strongest? 

In the corners and along the sides. 


Locomotive Fuel Economy 


45 


GRAPHIC ILLUSTRATIONS OF DIFFERENT WAYS OF 
THROWING COAL INTO THE FIREBOX. 



Figure No. 5 shows the system of Heavy Firing at the Furnace 
Door, resulting in a Bright Fire over a portion only, 
with a consequent reduction of Fire Box Temperature. 



Figure No. 6 shows a system of Shallow and Level Cross Firing 
with slight building up around the edges, producing a 
Bright Fire throughout, with High Temperature 
within the whole Fire Box. 

















































46 


Locomotive Fuel Economy 



Figure No. 7, shows the effect of the temporary reduction in Fire 
Box Temperature when a shovel of coal is introduced. 



Figure No. 8, shows the reduced temperature restored at the time 
the second shovelful is introduced, as would be the case 
with the system of Cross-Firing. 














































Locomotive Fuel Economy 


47 



Figure No. 9 shows the piling 
of the coal on the side as 
would be the result of Cross- 
Firing. 



Figure No. 10 shows the action 
of the draft in thinning fire 
along the walls of the Fire 
Box and the edge of fire unless 
piled, as per figure No. 5. 



Figure No. 11 shows the method of Cross-Firing as indicated by 
successive numbers on the arrows, first firing on one side and 
then the other, along the walls of Fire Box. 


































48 


Locomotive Fuel Economy 


122. (T-48) How should the coal be placed on 
the fire—in a heap, or evenly and lightly spread? 

Evenly and spread lightly all over. 

123. (T-49) What is a “bank” in a fire? 

A sure proof of poor firing. It is caused by 
putting more coal on some portion than it can im¬ 
mediately burn. Coal that should have spread over 
ten or fifteen square feet has been carelessly dumped 
in to cover only three or four square feet. 

124. (T-49) How is it caused? 

By earless firing. 

125. (T-49) Who is responsible for it? 

The fireman. 

126. (T-49) Is it good for steam making? 

It is not. 

127. (T-49) How does it affect steam making? 

It retards quick steam making. 

128. (T-49) Does it add greatly to the heat be¬ 
ing produced by the fire? 

It does not. A bank of unburned coal acts much 
like a blanket. It serves to prevent combustion. It 
practically puts out of action all the fire surface 
it covers. It is an enemy of economical use of fuel 
and prevents quick steam making. 

129. (T-49) If so explain how, and if not ex¬ 
plain why. 

During the time the fire’s surface is covered or 
smothered by a bank the other portions have to do 
more than their proper amount of work and that 
causes too rapid combustion and results in loss. A 
bank in the fire often starts a clinker formation. 

130. (T-49) What should be done with banks? 

Broken up and spread out with the hoe to burn. 


Locomotive Fuel Economy 


49 


131. (T-49) Should more coal be put on banks 
before or immediately after they are spread? 

No, not more coal, but more time is needed. 

132. (T-50) Describe perfect firing. 

Perfect firing is to fire lightly and spread evenly, 
putting in one shovelful at a time, placing each in 
a different place, alternately. Using good judgment 
regarding where to put coal on the bed according to 
its appearance and according to the work the engine 
has to do. The coal should be well broken. 

133. (T-50) Ordinarily how many shovelfuls of 
coal should be put in per “fire?” 

Properly only one, never more than two. 

134. (T-50) Why does this method produce the 
best results? 

It causes less smoke and makes a steady steam 
pressure with less coal than when larger charges 
are put in. 

135. (T-51) To what size should lumps of coal 
be broken? 

About the size of ordinary apples. 

136. (T-51) Why does breaking coal into small 
lumps aid its burning? 

Because there is more surface thus exposed to the 
action of the oxygen of the atmosphere, which as¬ 
sists rapid burning and the production of intense 
heat. 


50 


Locomotive Fuel Economy 


LESSON XIII.—FIRING WITH BITUMINOUS 
COAL—Continued. 

137. (T-52) Describe heavy firing. 

It is throwing in too much coal at a time. 

138. (T-52) What are its results? 

Shuts off air, cools the fire, lowers the tempera¬ 
ture of the boiler. 

139. (T-52) Why are these wasteful and dam¬ 
aging? 

It causes imperfect combustion. Gases escape up 
the stack without having yielded heat units, causing 
wasteful loss. The contraction of the boiler parts 
due to reduced temperature causes damage to tubes 
and tube sheets or to staybolts because there is a 
sudden expansion or stretching when the big 
charges finally begin to burn fiercely. 

140. (T-53) Should a “fire” be put in hastily or 
leisurely? 

Leisurely. 

141. (T-54) Is “pulling” the fire an unavoidable 
accident, or is it the result of carelessness and 
neglect? 

It results from carelessness and neglect. 

142. (T-54) Who is to blame? 

Both the engineer and fireman. It is very harmful 
to have a fire “pulled” by heavy exhausts when 
starting. Such mishaps cause serious delays to 
trains. It should be prevented by being everlastingly 
on the watch to keep the fire in good condition all 
the time. 

143. (T-54) What treatment is necessary to re¬ 
store the fire to proper working conditions? 

The fireman must notify the engineer who will at 
once ease off the steam. If steam must be used the 


Locomotive Fuel Economy 


51 


dampers must be immediately closed and the fire 
door put on the latch. Then coal enough to hold 
the fire without smothering it must be put in. The 
door again put on the latch and the blower used to 
build up the fire. While the exhausts are heavy the 
dampers must be kept shut to prevent the strong 
blasts of air from going through the fire. 

144. (T-55) How much coal is usually wasted 

when the safety-valve operates? 

A quarter pound each second. 

★ 145. (T-55) With coal costing $2.50 per ton, 

estimate the loss of coal and money when an engine 
pops sixty-two times a day—for a month. 

It amounts to about 8 tons of coal, which would 
cost $20.00. This shows how important it is to 
keep an even steam pressure while the locomotive 
is running. Changes of pressure interfere with the 
proper working of the engine. So while sufficient 
steam pressure should be maintained, yet no surplus 
steam should be generated to blow away through 
the “pop” or safety valve without having done any 
work and resulting in loss of fuel needlessly burned. 

146. (T-56) How can “popping” be prevented? 

By the exercise of good judgment in so feeding 
the fire according to the work to be done as to keep 
an even steam pressure. 

147. (T-56) What evil results follow from a 
wide-open fire-door when the engine is working? 

The howling “pop,” indicating carelessness and 
bad judgment. 

148. (T-56) Why does dropping the dampers 
decrease the heat of the fire? 

It temporarily suspends combustion. 


52 


Locomotive Fuel Economy 


LESSON XIV.—FIRING WITH BITUMINOUS 
COAL—Concluded. 

149. (T-57) Why are wide fire-boxes used? 

To give more grate surface and permit of a softer 
draft. 

150. (T-57) Should wide fire-boxes carry deeper 
or thinner fires than narrow fire-boxes? 

Thinner fire-beds. 

151. (T-57) Should a fire in a wide fire-box be 
“fired” more heavily or more lightly than in a nar¬ 
row fire-box? 

It should be fired more lightly. 

152. (T-58) What is smoke? 

A mixture of gases and carbon. 

153. (T-58) Why is smoke about depots objec¬ 
tionable? 

It annoys patrons of the company and is regarded 
as a nuisance. 

154. (T-58) How can it be prevented at such 
places? 

By building up the fire gradually—scattering one 
or two scoopfuls of fine coal over the surface and 
with the door ajar or blower on a little, if needed, 
give time for the gas to escape and burn before 
putting more coal in. 

155. (T-58) Why is smoke objectionable when 
trailing back over trains after steam is shut off? 

It annoys passengers—and on freight trains 
obscures the vision of the trainmen. 

156. (T-58) How can it be prevented at such 
times? 

By opening the fire door and using the blower as 
much as necessary. 



Locomotive Fuel Economy 


53 


157. (T-59) Is “drumming” a desirable noise 
about passenger trains? 

It is not. 

158. (T-59) How can it be prevented? 

By closing one or both dampers, or opening fire 
door enough to stop it, whichever seems to accom¬ 
plish it best. 


SECOND EXAMINATION 

ECONOMICAL BOILER-FEEDING 


LESSON XV.—IMPORTANCE OF BOILER¬ 
FEEDING. 

159. (T-61) What is an engineer’s first duty? 

To be always watchful and anxious for the safety 
of his engine and train. 

160. (T-62) What is the most important part of 
a locomotive? 

The boiler. 

161. (T-63) What is the most important phase 
(or matter) of locomotive management? 

Boiler feeding. 

162. (T-62) Within what limits should the 
steam pressure be kept while running? 

Within the limits of about ten pounds. 

★ 163. (T-63) What is the difference of tempera¬ 
ture between steam of 100 and 245 pound pressure? 

There is a difference of 66.5 degrees because at 
100 pounds steam pressure the temperature is 338 
degrees while at 245 pounds steam pressure the tem¬ 
perature is 404.5 degrees. 

164. (T-63) What effect does a very high tem¬ 
perature have on boiler plates? 

It rapidly weakens them. 

165. (T-63) How do locomotive boiler explo¬ 
sions occur? In connection with this question study 
the following table. 

Through some portion of the heating surface be¬ 
coming bared to the heat of the fire while under 





Locomotive Fuel Economy 


55 


pressure. In a very short time the metal becomes 
heated and weakened enough to give way under the 
heavy pressure upon it. Weakening starts when 
wrought iron or steel boiler plates are heated above 
400 degrees, which is the temperature of steam at 
235 pounds pressure. When the temperature is 
raised above 400 degrees weakening goes on very 
rapidly, increasing with the temperature until the 
plates melt. When a thousand degrees hot their 
strength is reduced eighty per cent, or four-fifths, so 
they would have only one-fifth the strength they had 
at temperatures between zero and 400 degrees. 

When water completely covers the heating sur¬ 
face of a boiler it is safe to assume there is no 
danger of overheating, as it is not likely the steam 
pressure will rise above 250 pounds. But with a 
hot fire and a bare crown-sheet it might take only 
ten or twenty seconds to heat the metal so that 
it would give way to the heavy pressure. For with 
150 pounds working pressure there is over ten tons 
pressure to EACH SQUARE FOOT of the crown- 
sheet. From that cause many locomotive boiler 
explosions have occurred according to authorities. 


TABLE SHOWING VARIATION OF TEMPERA¬ 
TURE OF BOILING WATER AND STEAM 
ACCOMPANYING VARIATION OF PRESSURE. 

Effective 
pressure 
per square 
inch. 

Tempera¬ 

tures. 

Effective 
pressure 
per square 
inch. 

Tempera¬ 

tures. 

Pounds. 

Atmos- ) 
pheric V 0 
pressure) jq 

20 

30 

40 

50 

60 

70 

80 

90 

100 

Degrees. 

212 

240 

259 

274 

287 

298 

307 

316 

324 ’ 

331 

338 

Pounds. 

110 

120 

130 

140 

150 

160 

170 

180 

205 

235 

245 

Degrees. 

344 

350 

355 

361 

366 

370 

375 

380 

390 

401 

404.5 











56 


Locomotive Fuel Economy 


166. (T-64) Is the work of locomotives very 
similar to stationary and marine engines? 

It is not. 

167. (T-64) How does the work differ? 

Stationary and marine engines have an almost 
constant steady amount of work to do. Locomotives 
have a constantly changing, irregular amount of 
work to perform. 

168. (T-64) Should the method of feeding loco¬ 
motive boilers be similar to the usual method of 
feeding stationary and marine boilers? 

No, it should not. 

169. (T-64) Describe good locomotive boiler- 
feeding. 

Locomotives should have water fed into their 
boilers while running into stations, or going down 
grades with steam shut off. Also while at a stand¬ 
still. The water should be injected with care and 
good judgment as to the amount so as not to cause 
too much variation in steam pressure, also to avoid 
priming. 

170. Describe your method. 

The student should be able to answer as follows: 

Starting with the glass two-thirds full, I shut off 
injector for half mile or a mile. Then with half a 
glass of water, the engine working easily and train 
running fast, I start injector again. 


Locomotive Fuel Economy 


57 


LESSON XVI.—BOILER-FEEDING—Continued. 

171. (T-65) What is meant by the term “atmos¬ 

pheric pressure?” 

The pressure (or weight) of the air of the atmos¬ 
phere at the level of the sea. 

★ 172. (T-65) At what temperature does water 

boil under atmospheric pressure? 

212 degrees. 

★ 173. (T-65) What is the weight of the air per 

square inch at sea level? 

14.7 pounds, but usually figured as about 15 
pounds. 

174. (T-65) The “boiling point” of water de¬ 
pends upon what condition? 

The pressure upon the water. 

175. (T-65) When water boils, which is the 
hottest—the water or the steam that comes from it? 

One is as hot as the other. 

★ 176. (T-65) When cool water is turned into 
steam of high pressure, what proportion of the nec¬ 
essary amount of heat to do this must be put into 
the water to RAISE it to the “BOILING POINT?” 

One-third. 

★ 177. (T-65) Then what proportion of the total 

necessary heat is required to TURN the boiling wa¬ 
ter INTO STEAM? 

Two-thirds. 

178. (T-65) Are these facts of much importance 

in locomotive boiler-feeding? 

They are of utmost importance. 

★ 179. (T-66) With an ordinary “wagon-top” 

boiler how much water can be held in the space 
within the boiler indicated by the water-glass? 

400 gallons. 


58 


Locomotive Fuel Economy 


★ 180. (T-66) How much water can be held in the 

space indicated by one inch of the water-glass? 

Forty gallons. 

★ 181. (T-66) How much heat can we store in 

this last named quantity of water? 

All the heat units yielded from an ordinary shovel 
of coal properly burned to secure perfect combus¬ 
tion. 

★ 182. (T-66) How much heat can we store in the 

first named quantity of water? 

All the heat obtained from the proper combustion 
of ten ordinary shovelfuls of coal. 

183. (T-67) Is such stored heat within the boiler 
of any advantage? 

It is. 

184. (T-67) How can it be used to save coal? 

It serves as a reserve or storage of heat to be 
drawn upon when there is extra hard work for the 
engine to do demanding an extra amount of steam. 
It then is not necessary to force the fire or use the 
injector and in that way coal is saved. 

185. (T-67) Why does an engine make steam 
more easily with the injector shut off than with it 
in operation? 

Because a third less heat is required from the fire 
than would be needed were the injector feeding in 
as much water into the boiler as is being used in 
steam. 

186. (T-67) When is the best time to put water 
into the boiler? 

When the desired pressure is regained. It could 
be worked finer if good judgment dictated until a 
favorable time for harder work. 

187. (T-67) Why is it economical to reduce the 
rate of combustion? 


Locomotive Fuel Economy 


59 


Because more pounds of water per square foot of 
grate surface per hour can be turned into steam 
from each pound of coal burned. 

188. (T-67) What must you be careful about re¬ 
garding the steam pressure when filling the boiler 
with water? 

To keep up an even, steady steam pressure. 

189. (T-67) Why is it necessary to keep the 
steam pressure steady? 

To prevent the contraction or expansion of the 
metal of the boiler and so avoid unnecessary dam¬ 
age. 

190. (T-68) When the water in the boiler is up 
to the working limit, how can surplus steam be 
stored? 

By opening the injector throttle and tank valve 
and allowing the excess steam to blow back into the 
tank. 


60 


Locomotive Fuel Economy 


LESSON XVII.—BOILER-FEEDING—Concluded 

191. (T-69) Should the injector ordinarily be 
permitted to inject more water than is being used 
as steam while running along normally? 

It should not. If more water than is being used as 
steam is injected into the boiler while the locomotive 
is doing ordinary work, particularly when running 
along a level track, much coal is wasted as a result, 
because the fire then has to be forced to give more 
heat than is needed. 

192. (T-69) Is it better practice to have it sup¬ 
ply a little less water than is being used as steam 
at such times, if practicable? 

Yes. The injector should be adjusted to supply 
slightly less water than needed to replace the water 
being used, provided the boiler is full enough to per¬ 
mit it, then when the engine is next shut off the 
boiler can be given more water to make up for it, 
by continuing the injection. 

193. (T-69) Should a boiler be as full as prac¬ 
ticable at starts? 

That depends upon what is meant by “practicable.” 
Only enough water should be kept to furnish the 
steam needed for the work to be done. Sometimes 
it is “practicable” to make enough steam with half 
a gauge of water, at other times more water may 
be necessary. 

194. (T-70) Should a boiler always be kept as 
full of water as possible? 

No; a half to three-fourths gauge is enough. It 
is good practice to let the water-level vary to suit 
the needs of the work the engine must do. It is 
not HOW MUCH water is in the boiler, but it is 
rather WHEN TO FEED water and how much to 
feed, because each pound of water uses just so much 
heat when being turned into steam, no matter 
whether it is one pound of a large or one pound of 
a small quantity of water. 


Locomotive Fuel Economy 


61 


195. (T-70) If the steam pressure lags while the 
engine is working, how can you remedy the matter 
most economically? 

By using good judgment as to how much and 
when to feed water and allowing the water level to 
vary freely according to the work. 

196. (T-70) In a case of necessity, which would 
you permit to vary (within safe and reasonable 
limits), the water-level or the steam pressure? 

The water level. 

197. (T-70) Can you save any coal by per¬ 
mitting the water-level to vary occasionally? 

Yes. Because each pound of water must have a 
given amount of heat supplied to convert it into 
steam. 

198. (T-70) Does it injure the boiler to do so? 

No. 

199. (T-70) Does it injure the boiler to permit 
the steam pressure to vary? 

Yes. 

200. (T-70) Why? 

Because it causes the temperature of the metal of 
the boiler to vary and if fire is forced or injector 
improperly used contraction and expansion occurs 
with consequent damage. 

201. (T-71) What are the proper limits of varia¬ 
tion of the water-level? 

Generally within two inches of the top and three 
inches of the bottom of the gauge glass. If a boiler 
is too full of water the space intended for steam is 
reduced, and consequently an unnecessary restric¬ 
tion of the amount of steam that could be formed is 
the result. Besides it causes water to be carried to 
the cylinders, because when the throttle is opened a 
large portion of the steam escapes, the pressure on 


62 


Locomotive Fuel Economy 


the surface of the water is suddenly reduced and 
violent boiling takes place; and this throws spray 
into the steam. 

202. (T-71) Do you understand that these In¬ 

structions and Rules for Boiler-Feeding are to be 
observed and enforced the same as the other Rules 
of the Management for the proper operation of the 
road? 

NOTE:—The “Instructions and Rules” mentioned 
are those furnished for study by the railroad com¬ 
pany. Upon them these questions and answers are 
based. The student should be able to answer truth¬ 
fully that he does. 


THIRD EXAMINATION 

ECONOMICAL USE OF STEAM 


LESSON XVIII. 

203. (T-72) The coal consumption of locomo¬ 

tives depends mainly on—What? 

The amount of steam used in doing the required 
work. 

★ 204. (T-72) How many cubic feet of steam, of 

atmospheric pressure, can one pound of water pro¬ 
duce? 

27 cubic feet. 

t^ 205. (T-72) How many cubic feet of steam of 

145 pounds pressure can one pound of water pro¬ 
duce? 

About 224 cubic feet. In other words, steam at 
150 lbs. pressure is compressed into a space one- 
tenth that of steam at atmospheric pressure. 

206. Considering the previous two questions and 
your answers—Is it plain to you why high pressure 
steam acts like a compressed spring in expanding? 

The student should have thoroughly studied, and 
by observation and experience as well, ought to be 
able to answer that he does. 

207. (T-72) What is meant by the term “full- 
stroke?” 

When the steam pushes the piston without ex¬ 
panding. At full stroke steam of LOW PRESSURE 
is used, obtained by throttling, or otherwise. It 
leaves the cylinder at the same pressure at which it 
enters, because there is no expansion. 

208. (T-72) What is meant by the term “cut¬ 
off” at 6 inches, or 8, 10 or 12 inches? 





•I 

es 

p 

p 

x 

i—i 

p 

o 

p 

X 

< 

H 

c/3 

W 

ffi 

u 

I 

WrH 

rZ 

< 

w 

H 

C/3 

W 

o 

p 

o 

OS 

K 

H 

W 

l-H 

> 

P 

< 

X 

o 

►—I 

H 

U 

W 

C/3 


55 

O 

i—i 

C/3 

5? 

< 

P 

X 

w 

P=H 

C 

w 

H 

c/3 

O 

X 

l-H 

H 

<1 

OS 

H 

c/3 

P 

P 

P 


C'j 

T-H 

d 

HH 

Ph 


cd 

oJ 

•G 


<u 

G 


flj 

<l> 

> +-* 

•3 v 

^ 4-> 

<U O cd 

fM ■+—* • »H 

* s 

. <D -G 

2^ <5 

-*-> ° 

CD CD 

■g 8 

•S 

«~.S< 

^p-rP 

rt ^S“X 

O W 
js " 
top* 
^x p~ 

°P ss 

oo 

O .52 H 


5X 


fi'oX 


W) -.rt 

.5^ 

° 

03 (f) 


«5 § 

03 


C/3 


g-g 

4— > G 

CD 03 CJ 

‘a ^ 
<u b 

P 03 

*£ £ 

Ih 
CD O 

o 

JG 

in 


\ 
















































































































































































Locomotive Fuel Economy 


65 


A six inch cut-off is a “short cut-off.” The others 
are “late cut-offs.” They allow the steam to expand 
in the cylinder after it is shut in. 

209. (T-72) What is meant by the term “expan¬ 
sive use of steam?” 

The expansive force exerted by the imprisoned 
steam as it rushes to get out pushing the piston as 
it expands just as a powerful compressed spring 
would when expanding. At a short cut-off steam of 
high pressure is admitted to the cylinder while the 
piston is moving over about the first quarter of the 
stroke—about six inches, at that moment steam from 
the boiler is shut off by the valve. The imprisoned 
steam instantly expands, the expansive force pushes 
the piston to the end of the stroke, increasing in 
volume four times but decreasing in pressure to only 
one-fourth what it was when cut-off. 

210. (T-72) How can steam be used expansively 
in a locomotive’s cylinder? 

By admitting a certain amount to the cylinder and 
cutting off the admission of any more by the action 
of the valve. 

Vr 211. (T-72) If steam throttled to 77 pounds 

pressure is admitted into an 18-inch cylinder during 
the full stroke of the piston—How much steam will 
be used in that stroke? 

Nearly six-tenths of a pound. 

★212. (T-72) If steam of a 140 pounds pressure 

is admitted through a wide open throttle during 6- 
inches of the stroke of the piston in the same cyl¬ 
inder and then cut off—How much steam will be 
used in that stroke? 

About three-tenths of a pound, or one-half LESS 
than at full stroke, yet the pressure on the piston, 
and the work done is the same in each case. 

★ 213. (T-72) About what portion of the heat im¬ 

parted to a pound of cold water to turn it into steam 
of 145 pounds pressure is converted into WORK in 
a locomotive’s cylinders? 


66 


Locomotive Fuel Economy 


About a fortieth part. The remainder, or thirty- 
nine fortieths, is lost through the exhausts. That 
is WHY every possible effort should be used to get 
from the expansive force all the energy or work it 
can be made to do before letting the steam escape 
through the exhausts. 

The best practice has been toward using higher 
pressures and greater expansion. That is WHY 
strongly built boilers carrying 200 lbs. pressure (and 
with closely-notched reverse-lever quadrants to give 
fine graduations of the cut-off) and compound cyl¬ 
inders are used. The expansive force of the steam is 
used twice in compounds, first in the high pressure 
cylinders and second in the low pressure cylinders, 
before being released through the exhaust. 

214. (T-73) After a train is started and as speed 
increases—How should the cut-off of steam be regu¬ 
lated, and to what extent? 

It should be cut off as “short” as possible con¬ 
sistent with the kind of work the engine is to do. 

215. (T-73) To make an engine do its best work 
with the shortest practicable cut-off—What is neces¬ 
sary to do with the throttle? 

When starting, work the engine full stroke, then 
throttle the steam to avoid slipping the driving 
wheels. When forcing the speed the throttle should 
be wide open, so steam may reach the cylinders at 
as near boiler pressure as possible, but it should be 
cut-off as early in the stroke as can consistently be 
done. It is bad practice and very wasteful to run 
with the reverse lever latched in the quadrant 
notches where the valves are caused to cut off at 
eight, ten, or twelve inches of the stroke, and by 
increasing or decreasing the pressure of the steam 
in the cylinders by the throttle. As much as vary¬ 
ing conditions permit the practice should be avoided. 

With the modern, close notched reverse lever 
quadrants and balanced valves there should be no 
reason for this wasteful practice. 


Locomotive Fuel Economy 


67 


216. Is this your practice? If not, frankly state 
the reason. 

(Students should answer according to their ex¬ 
perience.) 

217. At about what point of the stroke does your 
“working notch” cause a cut-off? 

(Answer this question from your own experience.) 

218. Are the three examples in this Lesson, show¬ 
ing the results of using steam in different ways, 
clear to you? 

The student should be able to answer that “they 
are” if he has studied them properly and coupled 
same with his observations and experience. 


THREE ILLUSTRATIVE EXAMPLES 

FIRST EXAMPLE—SIX-INCH CUT-OFF 

(From Railway Educational Association’s Manual.) 

“With an engine having cylinders 18 by 24 inches, 
and 145 pounds boiler pressure, we admit steam of 140 
pounds pressure THROUGH A WIDE-OPEN THROT¬ 
TLE to the cylinders until cut off at SIX inches of the 
stroke. 

‘We will watch the work of the steam in one cyl¬ 
inder, which will show what takes place in both. 

“The smooth face of the piston presents a surface of 
254% SQUARE INCHES. Each inch the piston moves 
leaves a space behind it of 254% CUBIC INCHES. In 
this way the volume and weight of steam in the cyl¬ 
inder at any point of the stroke may be measured, as 
the weight of any volume of steam of any given pres¬ 
sure is known. 

“Our cut-off is SIX inches, and when the piston has 
moved six inches of the stroke we have admitted 
nearly nine-tenths of a cubic foot of steam, which at 
this pressure weighs three-tenths (.3129) of a pound. 

“Steam is cut off from the cylinder by the valve at 
this point, the portion of it imprisoned in the cylinder 
acting like a compressed spring overcomes the re¬ 
sistance of the piston, and in forcing it to the end of 
the stroke expands to FOUR times its volume, and 
decreasing in pressure as it expands, is, at nearly the 
end of the stroke, exhausted at a pressure of 35 
pounds. 



68 


Locomotive Fuel Economy 


“The average pressure upon the piston during the 
stroke was 77 pounds per square inch.” 


SECOND EXAMPLE—EIGHT-INCH CIJT-OFF. 

“With the same engine and cylinder an^ pressure in 
the boiler, we admit steam to EIGHT INCHES of the 
stroke before cutting it off; and as we only wish the 
engine to perform the same amount of work as in the 
first example, we must throttle the steam, and RE¬ 
DUCE ITS PRESSURE as it enters the cylinder to 

117 pounds. ^ ^ . . , . . 

“This pressure will, when cut off at eight inches, 
cause 77 pounds average pressure on the piston during 
the stroke. In allowing the steam to follow the piston 
eight inches of its stroke we admit 1.18 cubic feet of 
steam, which at this pressure weighs a little over one- 
third (.347) of a pound. In this case, while doing the 
same work, we have used three-hundredths (.0342) of 
a pound of steam MORE than in the first example. 

“The steam in this case expands to but THREE 
times its volume and escapes through the exhaust at 
39 pounds pressure. We have measured the loss for 

one stroke of one piston; let us measure the loss for 

a complete revolution of the driving-wheels, during 
which each piston would make two strokes—four in 
all; so 4x.0342 equals .1364—over an eighth of a 
pound. . . 

“If our driving-wheels are 63 inches in diameter 

they will revolve 320 times in running one mile. As 
we are wasting an eighth of a pound of steam per 
revolution, we will waste 320X.1364 equals 43.6 pounds 
of steam in running one mile under the conditions of 
this example.” 


THIRD EXAMPLE—TEN-INCH CUT-OFF 

“We will in this case allow the steam to follow the 
piston TEN INCHES of the stroke before cutting it 
off, and we will throttle the steam still more than 
in the last example, so that the engine shall perform 
the same amount of work. 

“The steam is throttled to 103 pounds pressure, 
which at this cut-off will cause an average pressure 
of 77 pounds. At this cut-off we admit 1.47 cubic feet 
of steam, which at this pressure weighs nearly half a 
pound (.403), five-hundredths (.056) of a pound more 
than in the last example, and nearly a tenth of a 
pound (.091) more than in the first example; yet the 
work done in each case has been the same. 

“In this last example steam would expand but TWO 
AND A HALF times and would escape up the stack at 
43 pounds pressure. 

“An engine run in this way one mile would waste 
116 pounds of steam as compared with the first ex¬ 
ample. Of course a pound of steam is a pound of 


Locomotive Fuel Economy 


69 


WATER turned into steam. As in locomotive practice 
we average about six pounds of water turned into 
steam per pound of coal burned, the 116 pounds of 
steam we are wasting per mile under the conditions 
of the last example, in DOING THE SAME WORK as 
in the first example, means a USELESS LOSS of 20 
pounds of coal per mile, amounting to a loss of A 
FULL TON OF COAL in a trip of 100 miles.” 

★ 219. (T-73, First Example) What was the weight 

of the quantity of steam used during the stroke de¬ 
scribed in this example? 

Three-tenths of a pound. 

if 220. (T-73, Second Example) What was the 
weight of the quantity of steam used during the 
stroke described in this example? 

A little more than one-third of a pound. 

^■221. (T-73, Third Example) What was the 
weight of the quantity of steam used during the 
stroke described in this example? 

Almost half a pound. 

222. Do you understand that the WORK done in 
the cylinder during these three imaginary perform¬ 
ances was exactly the same? 

The student should have a thoroughly clear un¬ 
derstanding so as to answer that he does. 

★ 223. (T-73, Third Example) How many pounds 

of water are converted into steam by the heat from 
one pound of coal, in ordinary locomotive practice? 

Six pounds. 

224. According to the three examples described 
in this Lesson—What is the most economical way to 
use steam in the cylinders of any steam engine? 

With a short or early cut-off, and a full throttle. 
Working the cut-off (hooking up or down) accord¬ 
ing to working requirements. 

if 225. Comparing the work done and steam used 
in the first and third examples—How many pounds 


70 


Locomotive Fuel Economy 


of STEAM are wasted per mile on an engine run¬ 
ning under the conditions described in the third 
example? 

116 pounds. 

*226. How many pounds of COAL are wasted per 
mile in the same case? 

Twenty pounds. 

* 227. How much does this amount to in a trip of 
100 miles? 

A full ton. 


Locomotive Fuel Economy 


71 


LESSON XIX.—USE OF STEAM—Continued. 

228. (T-74) What is cylinder condensation? 

Some of the steam condensing in the cylinder and 
becoming water. 

229. (T-74) What causes cylinder condensation? 

(Before answering study the following table): 

TABLE COMPARING THE TEMPERATURE OP 
INITIAL AND EXHAUST STEAM, AND SHOW- 



ING 

THE CAUSE OF CYLINDER 


Effective 

CONDENSATION 

Pressure. Temperatures. 

Difference of 
Temperature. 

L i 

[Initial, 

103 lbs. 

.339.9°) 

. 49.6° 

t Exhaust, 

43 “ . 


II. 1 

[Initial, 

117 “ . 

.348.3°) 

. 62.4° 

| Exhaust, 

39 “ . 


III. j 

[Initial, 

140 “ . 

.361.0°) 

. 80.0° 

I Exhaust, 

35 “ . 

.281.0°f 

IV. j 

[Initial, 

245 “ . 

.404.5°) 

.192.0° 

'Exhaust, 

0 “ . 

.212.0° i ' 


The metal of the cylinders take heat from the 
steam and conduct it away. It is a source of loss. 
Usually the condensation increases as the cut-off is 
shortened. It is present in all cylinders of engines 
running with an early cut-off. Cylinder condensa¬ 
tion limits the economical use of the expansive force 
of steam. That is WHY compound cylinders are 
necessary. 

★ 230. (T-74) What is the difference of tempera¬ 

ture between steam of 140 pounds INITIAL pres¬ 
sure and 35 pounds EXHAUST pressure? 

80 degrees. 

★ 231. (T-74) What would be the difference be¬ 

tween the temperature of steam admitted to the cyl¬ 
inder at 245 pounds pressure, and reduced during the 
stroke to atmospheric pressure? 

192 degrees. 

NOTE:—Refer to the third example in Lesson No. 18. 
and notice that steam was admitted to the cylinder at 
















72 


Locomotive Fuel Economy 


103 pounds pressure and exhausted at 43 pounds pres¬ 
sure. Now consult Group No. 1 in the above table and 
notice that the temperature of the steam was 339.9 
degrees when admitted to the cylinder at 103 pounds 
pressure,—and that when it was exhausted its tem¬ 
perature was 290.4 degrees,—a difference of nearly 
fifty degrees. 

Remember, too, that the temperature of any pressure 
of steam is taken by the surface of whatever metal it 
comes in contact with, although it be in contact only 
a very short time, even as little as the fraction of a 
second. Therefore, the temperature would be changed 
very much if there were very wide differences of tem¬ 
perature between the steam and the surface of the 
metal with which it comes in contact. For example: 
if the metal were very cold and the steam very hot, 
the metal would be greatly heated, but the steam 
would be severely chilled, and that would cause some 
of the steam to CONDENSE to water. When the 
“initial pressure” and temperature of the steam ad¬ 
mitted to a cylinder are very high and the exhaust 
pressure and temperature are very low it indicates 
that exactly this form of condensation has taken place. 
T'he “fall of temperature” from its initial to its exhaust 
degrees of heat has given to the walls of the cylinder 
the heat of its lowest or exhaust temperature. The 
cylinder head and about six inches of the cylinder 
walls at the exhaust end have been made about fifty 
degrees colder than at the other (or initial) end of 
the cylinder. Bad results would not follow were the 
steam always admitted and exhausted from the same 
ends of the cylinder, which of course is not done. 
Hence the chilled end of the cylinder is a moment 
later in contact with the initial pressure steam of a 
new stroke. 

Referring again to the third example in Lesson No. 
18 it will be seen the initial-pressure steam for the 
new stroke on entering the cylinder would come in 
contact with metal surfaces about fifty degrees colder 
than its own temperature. 

In locomotive practice the steam used is always 
ready to condense into water directly heat is taken 
from it IN ANY WAY. Thus when new hot (initial- 
pressure) steam comes in contact with the colder 
cylinder-surface a portion is condensed to water, and 
there is what is called “Cylinder Condensation.” 

Look now at the second example, Lesson No. 18, and 
notice Group 2, in the table. The temperature of the 
initial steam is 348.3 degrees, the exhaust steam tem¬ 
perature is 285.9 degrees;—a difference of 62.4 degrees. 
Notice Group 3 in the same table; it shows the dif¬ 
ference in temperature between the initial and exhaust 
pressures of the steam as described in the first ex¬ 
ample;—the difference being 80 degrees. 


Locomotive Fuel Economy 


73 


It should be clear that while in the second example 
more steam and heat were used for a certain amount 
of work than were needed in the first example; and 
more were used in the third example than in the sec¬ 
ond example, the loss because of cylinder condensa¬ 
tion was greater in the first example than in the two 
others. 

Group 4 in the table is intended to make this quite 
plain. Steam of 245 pounds pressure is supposed to 
be admitted to a cylinder. It is cut-off and made to 
expand until, at the end of the stroke its pressure is 
equal only to that of the atmosphere. Its initial tem¬ 
perature would be 404 degrees, its exhaust tempera¬ 
ture 212 degrees;—or 192 degrees colder than it was 
when admitted to the cylinder. Now, at the start of a 
new stroke if steam of great heat rushes into contact 
with cylinder surfaces 192 degrees colder than its own 
heat, the result would be a great amount of cylinder 
condensation causing much waste. 

Hence the value of compound cylinders, in which to 
use steam which expands to many times its initial 
VOLUME. 

Nevertheless, in locomotive practice the only limit 
to the extent to which steam may properly be USED 
EXPANSIVELY is the NATURE AND AMOUNT OF 
THE WORK TO BE DONE. The advantages of using 
the expansive force of steam to the greatest possible 
extent are not alone the saving of heat in the quantity 
of steam used. There are other important advantages 
that MORE than offset all the evils of cylinder con¬ 
densation, as will be explained. 

Refer again to the three examples of using steam. 
Recall that with a six-inch cut-off the exhaust steam 
left the cylinder at 35 pounds pressure; with an eight- 
inch at 39 pounds; and with a ten-inch at 43 pounds; 
the pressure increased as the length of the cut-off 
was INCREASED. 

Since the escaping exhausts are used, in locomotive 
practice, to create the forced draft through the fire, 
a FOUR-FOLD ADVANTAGE IS GAINED, by using 
steam of high initial pressure, with early cmt-offs, be¬ 
cause: 

1st. There is less steam in the cylinders to be ex¬ 
hausted. 

2nd. Being at a lower pressure it is exhausted more 
easily. 

3rd There is a more full escape of steam, therefore 
there is less steam to be reimprisoned in the cylinder 
to cause back pressure. 

4th. Leaving the nozzle at a lower pressure, gives 
less force to the exhausts, thus creating a milder draft 
through the fire; resulting in fuel economy, because 


74 


Locomotive Fuel Economy 


it allows time for the hot gases from the fire to pass 
through the tubes less hurriedly, hence they are in 
contact with the heating surface longer, therefore more 
heat is given to the water in the boiler, because more 
TIME is allowed for HEAT TO PASS THROUGH THE 
METAL. 

232. (T-74) Why are “Compound” cylinders 
used in steam engines? 

Because with two or more cylinders there is less 
danger of condensation and of great differences be¬ 
tween temperature of the initial and exhaust steam 
in any one of the cylinders. 

★ 233. (T-75) Name four advantages, exclusive of 

economy of steam, which result from using high- 
pressure steam with short cut-offs, as compared with 
throttled steam and late cut-offs. 

(1) There is less steam in the cylinders to be ex¬ 
hausted. (2) Being at a lower pressure it is more 
easily exhausted. (3) The steam more fully escapes 
from cylinder so there is less to be reimprisoned and 
to cause back pressure. (4) As it escapes through 
the nozzle at a lower pressure there is less force of 
the exhausts and consequently a milder draft 
through the fire which materially aids combustion. 


Locomotive Fuel Economy 


75 


LESSON XX.-USE OF STEAM—Concluded. 
WHAT THE INDICATOR SHOWS. 

An indicator consists of a steam cylinder A and a 
paper-drum B. Within the cylinder is a piston which 
the pressure of steam admitted beneath it pushes 
upward. This upward movement compresses a 
spiral spring within the cylinder. When the steam 
pressure underneath the pistol falls, this spring ex¬ 
pands and pushes the piston downward again. Steam 



FIG. 13. A LOCOMOTIVE INDICATOR. 














76 


Locomotive Fuel Economy 


is conducted from the cylinder of the engine through 
a pipe of the engine to the indicator cylinder, where 
it is admitted at the bottom, C. 

Through the steam pressure below and the ex¬ 
pansion of the compressed spring above, the indi¬ 
cator piston is caused to move up and down, corre¬ 
sponding EXACTLY with the varying steam pres¬ 
sure in the CYLINDER OF THE ENGINE while 
working. 

The purpose of an indicator is to RECORD the 
pressure variations exerted in the cylinder of an 
engine during certain strokes of its piston. This is 
done by means of the upright rod D attached to the 
top of the indicator piston through which it gets its 
upward and downward movements. 

The movements of the piston-rod are made 
through the link E to the lever F, which at G holds 
a pencil. There is a curved slot inside the upright 
piece H in which a roller attached to the lever F 
moves. It is held so that a pencil draws a 
STRAIGHT LINE up and down, instead of a 
curved one. 

The paper-drum B will revolve forward and back¬ 
ward. It is covered with a sheet of paper, or, as it 
is called, indicator card. When steam is admitted 
to the indicator cylinder, its piston RISES and 
pushes up the lever F, causing the pencil to draw a 
line on the card to INDICATE THE STEAM 
PRESSURE which is shown by the height it reaches. 

When the drum is revolved before steam has been 
admitted to the indicator, the pencil which is resting 
at its lowest position, draws a STRAIGHT line 
around the card on the drum, near the bottom. This 
is called the “ATMOSPHERIC LINE” because no 
pressure but that of the ATMOSPHERE is then 
active in the instrument. 

When the drum again revolves while steam of 
STEADY pressure is admitted to the indicator, the 
pencil RISES and draws a parallel line ABOVE the 
atmospheric line at a height to correspond with the 


Locomotive Fuel Economy 


77 


PRESSURE of the steam above the ATMOS¬ 
PHERE. Should there be a rise or fall of steam 
pressure during the revolution of the drum the 
pencil moves correspondingly up or down, and IN¬ 
DICATES the variations on the card. 

This records and shows what takes place in the 
cylinders of working locomotives and other steam 
engines. 

The cord I which encircles the drum is attached 
to a lever which receives a “to and fro” motion from 
the engine cross-head. This cord can pull the drum 
around only one way, so a coiled spring is placed 
inside the drum to draw it back when the cord is 
relaxed. Thus the drum is made to revolve ONCE 
while the cross-head is making ONE stroke. 

The tension of the spring exactly balances the 
steam pressure that compresses it. As the drum is 
revolved by the stroke of the cross-head, the pencil 
traces on the card an ACCURATE RECORD of 
what the steam does in the cylinder of the locomo¬ 
tive during any stroke of the piston. 


Diagram (Fig. 14) is the record an indicator would 
make showing the action of steam in a locomotive 
cylinder during a stroke of its piston under sup¬ 
posedly perfect conditions. The piston is at the 
beginning of a stroke. The throttle is open, ad¬ 
mitting steam of 150 pounds pressure to the cyl¬ 
inders of both engine and indicator. The pistons in 
each move. The indicator piston rises and makes 
the pencil draw the perpendicular “ADMISSION 
LINE” on the card from X to A to a height show¬ 
ing 150 pounds pressure. 

As the cross-head moves on its stroke, the drum 
revolves, and the pencil draws the horizontal 
“STEAM LINE,” A to B, during the first eight 
inches of the stroke. Steam is cut off at eight 
inches. Expanding it falls in pressure. The pencil 
draws the “EXPANSION CURVE, from B to C, 
until at seventeen inches of the stroke the exhaust 
port is opened. Now the pencil, suddenly falling 


POUNDS PRESSURE 


78 


Locomotive Fuel Economy 



DIAGRAM FIG. 14. THEORETICALLY PERFECT. 


with the pressure, draws the “EXHAUST LINE,” 
C to E, to the end of the stroke, twenty-four inches. 

When the return stroke begins all the steam of 
the stroke just finished has escaped from the cyl¬ 
inder, so the pencil falls to the atmospheric line. Re¬ 
turning as the drum is drawn back by the spring 
inside, it draws the “BACK PRESSURE LINE,” 
E to F, above the atmospheric line. This indicates 
NO back pressure; but near the end of this stroke, 
the exhaust port is closed and the imprisoned AIR 
in the cylinder, compressed by the advancing piston, 
increases in pressure, and the pencil draws the 
“COMPRESSION CURVE,” F to G. One inch be¬ 
fore the piston reaches the end of this stroke, the 
valve opens the steam port and the pencil draws the 
“PRE-ADMISSION LINE,” G to H. 

ACTUAL PROOF OF THE ECONOMY OF 
SHORT CUT-OFFS IN PRACTICE. 

The diagrams shown here, Nos. 15 and 16, were 
made by an indicator on a locomotive in passenger 
service. They illustrate the economy of short cut¬ 
offs. 






































FOUNDS PRESSURE 


Locomotive Fuel Economy 


79 


DIAGRAM NO. 15—FULL THROTTLE. 

In the case of diagram No. 15 the boiler pressure 
was 145 pounds. The throttle was WIDE OPEN 
admitting to the cylinders steam of 140 pounds pres¬ 
sure. The cut-off was at EIGHT INCHES of the 
stroke. The steam was exhausted at 38 pounds 
pressure, at 18 inches of the stroke. There was an 
average pressure of 70 pounds, 186 horse-power, at 
a speed of 28 miles per hour. 

The cylinder was 19 by 24 inches. The smooth 
face of the piston presented a surface of 283.6 square 
inches. For each inch the piston moved, the space 
left behind was 283.6 cubic inches. 

At the point of the stroke where the exhaust com¬ 
menced there were 2.95 cubic feet of steam in the 
cylinder, of 38 pounds pressure, weighing over a 
third of a pound (.374), the weight of steam used in 
the stroke. 

< _STROKE OF PISTON - INCHES_. 

ISO- 
140 ' 

ISO- 
120 - 
110 - 
100 - 
80- 
60 - 
70 - 
C0- 
60 - 
40 - 
30 - 
20 - 
10 - 
0* 


Showing steam of 140 pounds pressure cut off at 8 inches of its 
stroke, the exhaust beginning within 6 inches of the end 
of stroke when the pressure was 38 pounds. 



Four times this amount, or one-and-a-half (1.5) 
pounds of steam were used in one revolution of the 
driving-wheels. The driving-wheels were 63 inches 














































80 


Locomotive Fuel Economy 


in diameter. They revolved 320 times while running 
one mile. Hence 320x1.5 equals 480 pounds of steam 
per mile were used by the engine while running 
under the condition shown. 

DIAGRAM (FIG. 16)—STEAM THROTTLED. 

DIAGRAM No. 16 was made on the same locomo¬ 
tive under the same conditions. In this case the 
boiler pressure was the same, 145 pounds. The 
steam was throttled to 130 pounds and was allowed 
to follow the piston ELEVEN INCHES of the 
stroke before it was cut off. 

At twenty inches of the stroke it was exhausted 
at a pressure of 53 pounds, so there was an average 
pressure of 75 pounds, 188 horse-power, at a speed 
of thirty miles per hour. 

_ STROKE OF PISTON - INCHES__ 


140- 
130- 
120 - 
“» 110 - 
3 loo- 

<o on- 

g 80- 

o 70- 
o 60- 


30- 

20 - 


0 - 

ATM03PHERIC LINE 

DIAGRAM FIG. 16. STEAM THROTTLED. 

Showing steam of 130 pounds pressure cut off at 11 inches of the 
stroke, the exhaust beginning within 4 inches of the end of 
the stroke when the pressure was 53 pounds. 



At the point of exhaust there were 3.28 cubic feet 
of steam in the cylinder, which at 53 pounds pres¬ 
sure weighed .526 of a pound, the amount used in 
this stroke. At each revolution 4x.526 equals 2.1 
































































Locomotive Fuel Economy 


81 


pounds of steam were used, and 320x2.1 equals 672 
pounds per mile. 

It can be seen therefore that the work done by 
the later cut-off, as shown in diagram No. 16, was 
rather more than with the early cut-off, as diagram 
No. 15 shows, but it was done at an EXTRAV¬ 
AGANT waste of steam and fuel, as may be seen 
by comparing the two. 

By the early cut-off, 480 pounds of steam were 
used per mile run. By the late cut-off, 672 pounds 
of steam were used per mile run. A difference of 
192 pounds of steam per mile. This difference took 
32 pounds of coal to convert water that was used 
into steam of boiler-pressure. 

Hence the excess of work was done at an expense 
of 32 pounds of coal per mile, AMOUNTING TO A 
TON AND A HALF IN A TRIP OF 100 MILES. 


STROKE OF PISTON - INCHES- 



COMBINATION DIAGRAM FIG. 17. 


Diagram Fig. 17 shows diagrams 15 and 16 together. 
Their differences may thus be easily compared. The 
dotted lines show diagram No. 15. The black lines 
show diagram No. 16. The top line in each diagram 
shows the STEAM PRESSURE in the cylinder dur¬ 
ing the stroke in which steam was used. The bottom 



























82 


Locomotive Fuel Economy 


line in each shows the BACK PRESSURE during 
the return stroke in which steam was EXHAUST¬ 
ED. The nearer approach of the bottom, or “Back 
Pressure Line," in diagram No. 15 to the “Atmos¬ 
pheric Line” reveals about SIX POUNDS LESS 
BACK PRESSURE as a result of using the SHORT 
CUT-OFF than in diagram No. 16, where a late cut¬ 
off was used. The conclusion must be obvious to 
any thinking man. 

★ 234. (T-77) Considering that six pounds of wa¬ 

ter are evaporated per pound of coal burned in usual 
locomotive practice—How much coal would an en¬ 
gine burn in running 3,000 miles under the condi¬ 
tions shown by diagram No. 15? 

240,000 pounds—120 tons. 

^235. (T-77) Measuring in the same way—How 

much coal would an engine burn in running 3,000 
miles under the conditions shown in diagram No. 16? 

336,000 pounds, 168 tons. 

★ 236. (T-77) With coal costing $2.50 a ton, state 

how much MONEY would be wasted in running an 
engine one month, or 3,000 miles, under the same 
conditions shown in Diagram No. 16 as compared 
with the same in Diagram No. 15? 

48 tons at $2.50—$120.00. 

237. (T-78) When an engine is working with 
the shortest practicable cut-off—Is it desirable to 
pull or keep the throttle full open, if the desired 
speed can be maintained with it PARTLY or 
NEARLY closed? 

It is not. 

238. (T-78) What is the most economical way 
to use steam on a locomotive while running along 
ordinarily? 

Run with wide open throttle and as short a cut¬ 
off as possible. Get away from stopping places 
easily so as not to work engine too hard. Make up 


Locomotive Fuel Economy 


83 


lost time after speed is gained out on the road. Never 
throttle down the pressure in cylinders unless en¬ 
gine is working fast with shortest possible cut-off 
than is needed to do the work in the required time. 


239. Do you understand that this whole subject 
ot using steam with as great expansion as possible, 
and, therefore, with as high pressure and as short 
cut-offs as are practicable, in order to save steam 
and fuel, is a matter for the exercise of good, care¬ 
ful, considerate JUDGMENT by an engineer, guided 
by a correct knowledge of conditions and desirous 
of operating his engine most efficiently and econom¬ 
ically? 


The student should be able to answer that he does. 


240. Is this your aim? 

The student ought to be able to answer that it is. 










. 













# 





















